It has been recognized for some time that the density and complexity of interconnections in printed circuit board technology can be increased substantially using multilevel structures. Printed circuits are formed on two or more levels and are interconnected through the board levels using through hole connections or, less typically, with edge connections. Not only is the interconnect density increased for a given board area, but crossovers are substantially simplified.
More recently it has been recognized that further savings in board area can be realized if circuit components as well as interconnects are located in interlevel sites in the MPCB. Typically these devices are thin film passive devices such as resistors, capacitors and inductors. See e.g., T. Lenihan et al, "Embedded Thin Film Resistor, Capacitors and Inductors in Flexible Polyimide Films", 1996 Electronic Components and Technology Conference (IEEE), pp. 119-124.
A simple and cost effective process for implementing this design concept would represent a significant advance in the technology.